The crossword answer most solvers report for “what causes bio change” is MUTAGEN (a factor that causes biological or genetic change).

Likely crossword answer

  • In biology, a mutagen is any physical or chemical agent that increases the frequency of mutations in DNA, such as radiation or certain chemicals.
  • Crossword clue databases group “subject to genetic change” and similar “bio change” wordings with mutation-related answers, especially MUTANT and MUTAGEN , but the one that means “what causes bio change” is MUTAGEN (the cause, not the result).

If your grid has:

  • 7 letters: it is very likely MUTAGEN.

If you share the pattern (e.g., “M _ T A G E N”) or letter count, the match can be confirmed more precisely. Information gathered from public forums or data available on the internet and portrayed here.